1. Field of the Invention
This invention relates to a storage tank to be connected to a hydrofoil and more particularly to an underwater storage tank for fuel and/or weapons which is readily detachable from a hydrofoil ship.
2. Description of the Prior Art
The development of hydrofoil ships has advanced dramatically in the recent past. Such ships are no longer merely of scientific interest, but are becoming a regular part of both commercial and military operations. In particular, the U.S. Navy has produced hydrofoil fighting ships for defense purposes. Such ships have advantages over conventional surface ships in terms of speed, motions and manueverability.
By design, most hydrofoils are small in size and light in weight in order to achieve design speed and in order to limit the size of the foils. As a result, the amount of fuel and payload which may be carried is limited. If the amount of fuel carried is limited, the range of the ship is correspondingly limited. Similarly, if the weapons payload is limited, the destructive capability of the ship is limited. Hence, current hydrofoils are limited in range and payload capability due to limits of size and weight.
Various ships have been designed in recent years having submerged or semi-submerged portions. U.S. Pat. No. 3,429,287 describes a ship made of a submerged portion and an upper portion connected by a hydrofoil system. This system allows faster speeds than conventional ships due to the removal of surface wave resistance, but does not achieve the speed and manueverability of true hydrofoil vessels. While the submersible portion may be utilized for any form of storage, it must be loaded by conventional techniques.
U.S. Pat. No. 3,842,772 describes a semisubmerged ship having one or more hulls to house machinery or crew quarters. While this design lessens the effect of waves and insures greater stability, it requires that any loading in the storage areas be accomplished by conventional techniques. Similarly, U.S. Pat. No. 3,897,744 describes a high speed semisubmerged ship which requires conventional loading. Neither of these ships rise out of the water like a true hydrofoil.